The invention relates generally to a feeder for documents which are to be franked in a postage meter, and relates particularly to an improved feeder which accomplishes reliable separation for individual feeding of documents from a stack even if they are of varying thicknesses and varying materials. The feeder is able to accommodate batches of documents, each batch being of documents of a particular size, but the feeder is readily adjustable to a different size of batch. Stated differently, the stack may be adjusted to one document size per batch.
A particularly difficult part of the design of any stacked document feeder is the separation of documents. It is critical that documents be passed one by one from the feeder to later equipment in the paper path, such as a postage meter. The passage of documents one by one permits the postage meter to frank each of them in a reliable way. It is important that misfeeds such as duplicate feeding of two or more documents be minimized or eliminated. It is desirable that the feeder be capable of feeding not only documents but also labels, which are used for applying postage to mail pieces that are unable to pass through the feeder and through the postage meter. It is also preferable that the feeder have a moistener with which envelopes may be moistened and sealed. With the moistener a typical problem is the need to replace parts of the moistener that age and need to be replaced, such as a sponge or brush. It is also desirable that any document jams in the feeder be easy to clear.
The many design goals just described must, of necessity, be fulfilled (if at all) within constraints of cost and size (form factor). It is thus particularly desirable to accomplish these many design goals at reasonable cost and while minimizing parts count and assembly steps.
A document feeder employs a lifting lever to lift stacked documents away from a feed roller each time a document is being fed away from the stack. In this way the separation of documents is enhanced, providing a mechanism that more readily accommodates documents of varying shapes, thicknesses, and materials. The feeder uses a motor linked by one-way clutches to feed mechanisms for documents and for labels, stacked separately. The motor is driven in one direction to feed documents and in the other direction to feed labels. A moistener is provided below the paper path, and the moistener is mounted so that it can be slidably removed. When it is removed, feed rollers are permitted to relax and move apart which helps in the clearing of jams.